Method of enhancing the information legibility of multi-color graphic material

ABSTRACT

The information legibility of multi-color graphic material is enhanced by a method illustrated as follows: Frames of panchromatic silver-halide black and white negative film are separately exposed through red, green, and blue transmitting filters respectively to an image of the original multi-color material. The negative images on the frames of film are developed and fixed, and then printed on respective red, green, and bluedye developing positive transparency materials. The red-dye, green-dye and blue-dye positive transparencies are then superimposed and retained in register. This invention relates in general to a method of enhancing the information legibility of multi-color graphic material, and in particular to a method of making a dark-field, positive fullcolor graphic from any of a wide variety of full-color graphics normally printed or otherwise available on white opaque or clear transparent backgrounds.

United States Patent [191 Domeshek 1 Dec. 31, 1974 METHOD OF ENHANCINGTHE INFORMATION LEGIBILITY OF MULTI-COLOR GRAPHIC MATERIAL [76]Inventor: Sol Domeshek, 24 Springfield Ave.,

Cranford, NJ. 07016 22 Filed: Jan. 31, 1973 21 Appl. No.: 328,182

[52] US. Cl 96/14, 96/17, 96/23, 96/45.1, 96/82 [51] Int. Cl G036 7/18,G03c l/92 [58] Field of Search 96/14, 11, 17, 16, 21-23, 96/30, 45.1, 2,82, 24

[56] References Cited UNITED STATES PATENTS 178,210 5/1976 2,336,56012/1943 2,507,494 5/1950 2,508,213 5/1950 2,787,543 4/1957 3,142,5637/1964 Alexander 96/2 FOREIGN PATENTS OR APPLICATIONS 2,973 7/1976 GreatBritain 96/14 OTHER PUBLICATIONS McGraw-Hill, The Focal Encyclopedia ofPhotography, Desk Edition, 1972, pages 293-296, 300-301, 306-307.

Photography, Its Materials and Processes, C. B. Neblette, D. Van NoStrand, 5th Ed., 1952.

Primary ExaminerNorman G. Torchin Assistant Examiner-Alfonso T. SuroPico Attorney, Agent, or Firm Roy E. Gordon; Eugene E. Stevens, 111;Frank J. Dynda 5 7 ABSTRACT ter.

This invention relates in general to a method of enhancing theinformation legibility of multi-color graphic material, and inparticular to a method of making a dark-field, positive full-colorgraphic from any of a wide variety of full-color graphics normallyprinted or otherwise available on white opaque or clear transparentbackgrounds.

8 Claims, 1 Drawing Figure METHOD OF ENHANCING THE INFORMATIONLEGIBILITY OF MULTI-COLOR GRAPHIC MATERIAL BACKGROUND OF THE INVENTIONHeretofore, dark-field, positive full-color graphics have been made byre-drawing the chosen colorgraphics manually in their original colorsbut with a low-noise or dark background and with white symbols andalpha-numerics wherever these appeared in black on the original graphic.Once such re-drafting has been done manually, conventional photographicprocedures could be employed in conventional sequence to prepare platesto reprint the dark-field graphic or to prepare full-colortransparencies or photo-prints of the dark field product. The difficultywith the above described method is that it is extremely time-consumingand extremely costly. If the color transfer into the low noise or darkbackground form is not carried out, the efficiency and effectiveness ofthe resulting color displays are largely reduced for many applications.

SUMMARY OF THE INVENTION The general object of this invention is toprovide a method of enhancing the information legibility of mu]-ti-color graphic material in which the various categories of informationare conveyed by natural or symbolic color codes against a white or clearbackground. A further object of the invention is to provide such amethod without disturbing the information content of the color-codes. Astill further object of the invention is to provide such a method inwhich the noninformation areas of the graphic material are transformedfrom a white or zero density and therefore, high noise intensitybackground to a black or high density and therefore, low noise intensitybackground. Another object of the invention is to provide such a methodin which the signal-to-noise ratio of all color-coded information withrespect to background is enhanced, thus enhancing the graphics contrastas well as its legibility.

According to the invention, all the foregoing objectives are attained bya method involving separately exposing frames of panchromaticallyphotosensitive, black-and-white, negatively recording, transparentmaterial (or transparencies) through red, green, and blue transmittingfilters respectively to an image of the original multi-color material.After developing and fixing these color-separated, black and white,negative im ages on the transparencies, these respectively red-, green-,and blue-filtered images are printed respectively on positive-imagingred-, green-, and blue-dye developing transparent materials. Thered-dye, greendye, and blue-dye positive image transparencies are thensuperimposed in any order and retained in register to obtain thedark-field, positive, full-color graphic.

DESCRIPTION OF THE DRAWING AND THE FIRST EMBODIMENT The invention canbest be understood by referring to the drawing which is a diagrammaticflow chart of a method according to the invention.

Referring to the drawing, the arrows therein represent the sequence ofthe method. The original graphic multi-color material, 10, such as astandard road map printed on white paper, is mounted on a copy board(not shown). A copy camera 12 with the first set of color-separationfilters, in this instance, a red-transmitting filter 14, mounted overthe lens is used to obtain an image of the original multi-color material10. The redtransmitting filter 14 may be characterized by a peakwavelength of 650 millimicrons, with a transmittance at that wavelengthof 88 percent, and a bandwidth of 590 to 690 millimicrons. The copycamera 12 is also loaded with a panchromatic, negative-imaging material16 such as panchromatic, silver-halide, black-and-white, photographicfilm. The negative film 16 is then exposed through red filter 14 mountedover the lens of the copy camera 12 to an image of the originalmulti-color material 10. The negative image on the film I6 is developed,fixed, and then printed on a photographic, positiveimaging, like-coloror red-dye-developing transparent material 18.

A red mark on the original multi-color graphic material 10 imagedthrough the red-transmitting filter 14 on the panchromatic,black-and-white, negatively recording material 16 appears on thatmaterial or colorless areas of low optical density as a relativelyhigh-density mark. White areas on the original multi-color graphic alsoappears as areas of high optical density on the neg ative material 16,and green and blue marks on the original 10 appear on the negativematerial 16 respectively with progressively lesser densities. Any blackor colorless high optical density markings on original multi-colorgraphic 10 appear as zero optical density areas on negative material 16.When the red-filtered negative image on film 16 is printed on thered-developing, positive-imaging film 18, the maximum density negativemarks that are red and white on the original multi-color graphic ltranslate as a maximum density red marks, and the progressively lesserdensity negative marks that are green and blue on the original show asprogressively lesser density red marks. The zero density negative marksthat are black on the original 10 show as clear or low optical density,colorless marks on the positive-imaging film 18.

The copy camera 12 is then loaded with a fresh frame of the panchromaticblack-and-white negative-imaging material 20 and the frame exposedthrough the second of a set of color-separation filters, in thisinstance, a green filter, 22 to an image of the original graphicmulti-color material 10 formed by the camera lens. The greentransmitting filter 22 may be characterized by a peak wavelength of 530millimicrons with a transmittance at that wavelength of 54 percent, anda bandwidth of 470 to 610 millimicrons. After development, thegreen-filtered black-and-white negative image 20 is printed onlike-color or green dye positive-imaging transparent material 24.

By analogy to the effects of the procedures traced through in the caseof the red-filtered imagery, the green-filtered process yieldsrelatively high-density green marks on the green-dyed positive image 24for each green and white mark on the original multi-color graphic l0,and lesser density marks on the green-dyed positive 24 for the blue andred marks on the original 10. Similarly, clear, colorless areas appearon positive 24 for all black markings on original 10.

The copy camera 12 is again reloaded with fresh panchromaticnegative-imaging black-and-white material 26, and an exposure of theoriginal multi-color graphic 10 is made through the third of a set ofcolor-separation filters; in this instance blue filter 28. The bluetransmitting filter 28 may be characterized by a peak wavelength of 430millimicrons with a transmittance at that wavelength of 50 percent, anda bandwidth of 400 to 510 millimicrons. The fixed blue-filtered,negative black-and-white image 26 is then printed on like-color blue dyepositive-imaging transparent material 30.

By analogy to the previous case, the results of the blue-dyepositive-image 30 exhibit the following characteristics:

High-density blue marks correspond to blue and white marks on theoriginal progressively lesser density blue marks correspond to green andred marks on the original 10; and clear, colorless marks correspond toblack areas on original 10.

The red-dye positive image transparency 18, the green-dye positive imagetransparency 24, and the blue-dye positive image transparency are thensuperimposed, in register and in any order, and bound to form a sandwich32. The sandwich then duplicates all colors as they appear in theoriginal multi-color graphic 10. However, in each dyed positive-imagetransparency of the sandwich, white areas of the original 10 appear ashigh-density red, green, or blue areas respectively. Thus, thesandwiched areas on 32 that were originally white on 10 appear asrelatively high density or dark areas due to the absorption ofsignificant portions of the red, green, and blue light in the overlaidtransparency layers. Conversely, since black on original 10 appears ineach dyed, positive transparency as clear and colorless, in the finalsandwich 32, all markings originally black in 10 appear as clear andcolorless in the sandwiched transparency.

Thus, all color information stays in its original positive color form,but the white field has been transformed to a high-density or darkfield, and all black lines, numerals, and text in the original appear ascolorless low-density or light imagery.

EXAMPLE II The same basic method is used as in the first embodimentexcept that a singleframe of commercially available integral tri-packcolor material, such as. Ektachrome or Ansco-Chrome, is used in place ofthe previously described sandwich 32 of complementarycolon separatedred-, green-, and blue-dye positive-imaging materials.

As is well known in the art, the general term Integral Tri-Pack iscommonly employed in photographic literature to designate a colorphotographic material in which three emulsions, each separatelysensitized to one of three primary colors, are coated over one anotheron the same base. The three emulsions are not separable and must behandled together during processing. This kind of material structure isapplied in modern color photography to reversal, negativepositive, andpaper print processes.

In the embodiment of this example, cyan-, magenta, and yellowtransmitting filters are used respectively as the set of first, second,and third color-separation filters. The cyan transmitting filter may becharacterized by peak wavelengths of 480 millimicrons and 700millimicrons with respective transmittances at those wavelengths of 53percent and 0.7 percent and respective bandwidths of 400 to 580millimicrons and 690 to 700 millimicrons. Similarly, the magentatransmitting filter may be characterized by peak wavelengths of 455millimicrons and 670 millimicrons with respective transmittances atthose wavelengths of 66 percent and 91 percent and respective bandwidthsof 400 to 520 millimicrons and 600 to 700 millimicrons; and the yellowtransmitting filter may be characterized by peak wavelengths of 315millimicrons and 580 millimicrons with respective transmittances atthose wavelengths of 1.5 percent and percent and respective bandwidthsof 300 to 340 millimicrons and 500 to 700 millimicrons. The resultingblack-and-white negative images are then transferred through red-,green-, and blue-light respectively onto a single frame of integralcolor tri-pack which, when processed, also shows all color informationin original color form while all white areas on the original 10 are darkand all black areas on the original 10 are clear and colorless.

The cyan, magenta, and yellow filters, in this embodiment leave originalred, green, and blue markings clear on the respective panchromaticnegative, black-andwhite recordings while white markings are dark andblack markings are clear on these recordings. These negatives nowrespectively exposed through red, green, and blue light onto thepositive-printing, integral color tri-pack will transfer to the colorrecording the original color information in the same sense while whiteand black are respectively reversed from the original to the copy.

EXAMPLE Ill In this embodiment, the basic method remains the same, butthe sequence of color-separated (e.g. red-, green-, and blue-filtered)negative images of the original multi-color graphic 10 is presentedagain through a panchromatic sensor on a phosphorescent screen whoseintensity and spectral output have been selected to satisfy the exposurerequirements of the family of positive-imaging, like-color e.g. red-,green-, and bluedye developing transparent materials respectively thatmay be employed. An example of means for the creation and presentationof the sequence of red-, green-, and blue-filtered phosphorescentinstead of silver-halide negative images of the original multi-colorgraphic 10 is illustrated by the contrast reversal of a panchromaticblack-andwhite televised scene to generate a negative image. Suchnegative output phosphorescent image has the requisite characteristicsto satisfy the requirements, for instance, of the red channel of thedark-field, full-color transparency when a panchromatic Black-and-WhiteTV camera scans the original multi-color graphic through a red filterwhile the phosphor in the output cathode ray tube yields sufficientultra-violet light to expose the red diazochrome foil to the cathode raytubes negative image.

Thus, in one hard-copy photographic step instead of two as in the firstembodiment or in Example II, the red-channel, diazochrome film image forthe darkfield, full-color transparency is obtained in hard copy form. Byanalogous procedure the greenand bluechannel diazochrome film images areeach obtained in a single hard-copy photographic step, and, as in thefirst embodiment, by superposing in register these three positive-image,color diazochrome films, the same final product is obtained, namely: adark-field transparency with all color information the same as in theoriginal graphic while original white areas are now dark and originalblack areas are now clear.

EXAMPLE lV By combining the process variations introduced in Examples IIand III, a further procedural economy is obtained. However, thiscombination itself is subject to differentiation as a function of thespecific equipment employed. Thus:

a. Cyan-, magenta-, and yellow-filtered negative images of the originalgraphic are presented in turn as in Example III on a white-light-outputphosphorescent screen which is used, through a corresponding successionof red, green, and blue filters, to expose a single frame of integraltri-pack, positive printing, color photographic material.

12. The sequence of color-separated images of the original multi-colorgraphic as in (a) above is presented for each color channel in turn as acorrespond ing-color, phosphorescent negative image via contrastreversal of each color channel of a full-color TV system. Without anyfurther filtering between the phosphorescent images and the integraltri-pack color photographic material, the tri-pack photo material isexposed in turn to each red, green and blue phosphorescent colornegative image as it is generated.

On development of the tri-pack material via exposure through either ofthe above procedures (a) or (b), a dark-field transparency is obtainedwith all color information the same as in the original graphic whilewhites and blacks on the original are reversed in the copy.

EXAMPLE V An additional variation of the inventions method for achievingdark-field, full-color graphics employs a combination of photographicand photo-engraving or photo-lithographic printing techniques. Note thattypically in these printing techniques, to making the printing plate, animage is formed by light-hardening of a photo-sensitive substance coatedon the plate. The exposing light makes this coating less soluble thanunexposed areas which are dissolved during development of the image onthe plate. On completing plate treatment by usual photo-engraving orphoto-lithographic techniques, ink will print from the plate only wherea protective image had been formed by the light-hardened coating.Conventional printing techniques, therefore, require sensitizedphoto-engraving or photolithographic plates to be exposed to negativeimages of the original graphic material that is to be printed inpositive form whether black and white or color. More over, forconventional full color reproduction, the color printing inks must alsobe the negative of the color separation filters.

For this variation, the inventions basic white-toblack field reversalprinciple, which retains all original colors in their positive sense inthe copy, is illustrated by the following procedure:

Three printing plates coated with panchromaticsensing, negative imaging,black-and-white photographic emulsion are exposed respectively throughhalftone screens to color-separated [c.g. red-, yellow-, and blue- (ormagenta-, yellow-, and cyan-)] filtered images of the originalmulti-colored graphic on white or clear background. On development,these printing plate emulsions leave images that protect the platesbeneath during the remaining litho-or engraving-plate preparation sothat each plate renders, in the same color ink, the patterns of thefilter-colored light that struck it and does not print where light didnot strike.

Thus, if the red, yellow, blue color-separation set is used, originalred and white prints as red; original yellow and white prints as yellow;and original blue and white as blue; while original black is not printedby any plate. The overprint of these plates on a white background thenyields red, yellow, and blue images corresponding to the patterns ofthese images on the original; the original white areas (with red, yellowand blue overprints) reproduce as dark background; and the originalblack-printed information, with no pigment or other coloring substanceon the copy, appears white.

A first modification to this variation of the invention occurs where thethree printing plates are coated with a negative-imaging photo emulsionwhich is only monochromatically sensitive, blue only for example. lnthis instance, the red-, yellow-, and blue- (or magenta-, yellow-, andcyan) filtered images of the original multicolored graphic on whitebackground are first recorded on panchromatic, black-and-white,negative-imaging photographic material; these respective colorseparatednegative records are each transformed to positive, color-separated,black-and-white images on another or intermediate set ofnegative-imaging blackand-white photo materials; and to this lastphotographic, color-separation set, the emulsions on the set of printingplates are exposed, developed, and the plates processed as before in thelitho or engraving process.

As before, the overprint of these plates using inks corresponding to thefilter color that led to each colorseparated plate yields areversed-field copy with original colors in their positive sense. it isto be noted that one photographic step may be saved if thecolorseparation from the original is accomplished onto panchromatic,positive-imaging, black-and-white, photographic material.

A second modification to this photographic/printing form of theinvention substitutes a positive-imaging, panchromatic-sensing,black-and-white, television system as the means to expose the printingplate emulsions respectively as the TV camera scans the originalmulticolor graphic through red, yellow, and blue (or magenta, yellow andcyan) color-separation filters. In all other respects, the procedure isthe same as in the initial case of Example V. l

The resulting opaque, dark-field, full-color graphic may be photographedby conventional techniques onto an integral, tri-pack color materialsuch as Ektachrome or Anschochrome to obtain a dark-field, full-colortransparency. Moreover, this combined photographic/- printing method issuited to applications requiring preparation of multiple copies of thedark-field, fullcolor graphics while the first embodiment and ExamplesI], III, and IV are more suited to preparation of single copies orreproduction of relatively small quantities of copies of the dark-field,full-color graphics.

As noted heretofore, the only way of accomplishing the same effect asachieved by this present invention is, at great cost of time and money,to re-draw manually the chosen color-graphics with low-noise backgroundand white symbols and text and then, as appropriate to the specificapplication, to reproduce that new graphic by such conventional means asis appropriate.

The old methods without such change as noted above do not achieve any ofthe effects achieved by the present invention because inherently, andthrough all conventional reproduction techniques as well, the highnoisebackground against which the color information must be preceived isfully retained.

The present invention, therefore, cannot be described as a change,addition, or improvement over an old method but rather constitutes aradical departure from the old method without which radical departurenone of the inventions effects could be achieved practically.

The dark-field full-color graphic prepared by the invention has use as amap slide in an aircraft navigation display device. In this device, thevideo from a rotorblade radar system may be directly combined at acathode ray tubes phosphor surface with an optically rearprojected andappropriately scaled image of the map of the area over which theaircraft is flying. This enables the aircraft crew not only instantly tocorrelate radar features with the map but also enhances direct radartarget identification, continuous aircraft positioning, and accuratelong term navigation independent of wind effects.

I wish it to be understood that I do not desire to be limited to theexact details of construction shown and described, for obviousmodifications will occur to a person skilled in the art.

What is claimed is:

1. Method of enhancing the information legibility of originalmulti-color graphic material, while retaining the colors of the originalbut reversing the density of the background of the original and thedensity of the black printed information of the original, said methodincluding the steps of A. separately exposing frames of panchromatic,

photo-sensitive, black-and-white, negatively recording material throughadditively colorseparating filters respectively to an image of theoriginal multi-color material,

B. developing and fixing the separate color-separated negative images,

C. printing these additively color-separated negative imagesrespectively on positive-imaging like-color developing transparentmaterials, and

D. superimposing, in register, the resultant positive imagetransparencies.

2. Method according to claim 1 wherein the additively color-separatingfilters are red, green, and blue transmitting filters, wherein theadditively colorseparated negative images are red, green, and bluefiltered negative images, and wherein the positiveimaging like-colordeveloping transparent materials are red, green, and blue dye developingtransparent materials.

3. Method of enhancing the information legibility of originalmulti-color graphic material, while retaining the colors of the originalbut reversing the density of the background of the original and thedensity of the black printed information of the original, said methodincluding the steps of A. separately exposing frames of panchromatic,photosensitive, black-and-white, negatively recording material throughsubtractively color-separating filters respectively to an image of theoriginal multicolor material,

B. developing and fixing the separate subtractively color-separationfiltered negative images, and

C. printing these subtractively color-separated negative imagesrespectively on a positive-imaging, integral tri-pack color materialthrough the corollary additively color-separation filtered white light.

4. Method according to claim 3 wherein the subtractivelycolor-separating filters are cyan, magenta, and yellow-transmittingfilters, wherein the subtractively color-separated negative images arecyan, magenta, and yellow filtered images, and wherein the corollaryadditively color-separated white light is red, green, and blue filteredwhite light.

5. Method of enhancing the information legibility of originalmulti-color graphic material, while retaining the colors of the originalbut reversing the density of the background of the original and thedensity of the black printed information of the original, said methodincluding the steps of A. separately exposing frames ofpositive-imaging,

additively color-separation dye developing, transparent materialsrespectively to like-color filtered, luminescent black-and-white,negative images of the original multi-color graphic and B.superimposing, in register, the additively colorseparated positive imagetransparencies.

6. Method according to claim 5 wherein the positive imaging,dye-developing transparent materials are red, green, and blue-dyedeveloping transparent materials, wherein the luminescentblack-and-white negative images are red, green, and blue filtered,luminescent black-and-white negative images, and wherein the positiveimage transparencies are red dye, green dye, and blue dye positive imagetransparencies.

7. Method of enhancing the information legibility of originalmulti-color graphic material, while retaining the colors of the originalbut reversing the density of the background of the original and thedensity of the black printed information of the original, said methodcomprising exposing a positive-imaging integral tri-pack colorphotographic material through red, green, and blue filters respectivelyto cyan-, magenta-, and yellowfiltered, luminescent, black-and-whitenegative images of the original multi-color graphic.

8. Method of enhancing the information legibility of originalmul'ti-color graphic materia, while retaining the colors of the originalbut reversing the density of the background of the original and thedensity of the black printed information of the original, said methodcomprising exposing a positive-imaging integral tri-pack colorphotographic material through the red, green, and blue channelsrespectively of a full-color reproducing, luminescent negative imagesystem to cyan-, magenta-, and yellow-filtered images of the originalmulti-color graphic.

1. METHOD OF ENHANCING THE INFORMATION LEGIBILITY OF ORIGINALMULTI-COLOR GRAPHIC MATERIAL, WHILE RETAINING THE COLORS OF THE ORIGINALBUT REVERSING THE DENSITY OF THE BACKGROUND OF THE ORIGINAL AND THEDENSITY OF THE BLACK PRINTED INFORMATION OF THE ORIGINAL, SAID METHODINCLUDING THE STEPS OF A. SEPARATELY EXPOSING FRAMES OF PANCHROMATIC,PHOTOSENSITIVE, BLACK-AND-WHITE, NEGATIVELY RECORDING MATERIAL THROUGHADDITIVELY COLOR-SEPARATING FILTERS RESPECTIVELY TO AN IMAGE OF THEORIGINAL MULTI-COLOR MATERIAL, B. DEVELOPING AND FIXING THE SEPARATECOLOR-SEPARATED NEGATIVE IMAGES, C. PRINTING THESE ADDITIVELYCOLOR-SEPARATED NEGATIVE IMAGES RESPECTIVELY ON POSITIVE-IMAGINGLIKE-COLOR DEVELOPING TRANSPARENT MATERIALS, AND D. SUPERIMPOSING, INREGISTER, THE RESULTANT POSITIVE IMAGE TRANSPARENCIES.
 2. Methodaccording to claim 1 wherein the additively color-separating filters arered, green, and blue transmitting filters, wherein the additivelycolor-separated negative images are red, green, and blue filterednegative images, and wherein the positive-imaging like-color developingtransparent materials are red, green, and blue dye developingtransparent materials.
 3. Method of enhancing the information legibilityof original multi-color graphic material, while retaining the colors ofthe original but reversing the density of the background of the originaland the density of the black printed information of the original, saidmethod including the steps of A. separately exposing frames ofpanchromatic, photosensitive, black-and-white, negatively recordingmaterial through subtractively color-separating filters respectively toan image of the original multi-color material, B. developing and fixingthe separate subtractively color-separation filtered negative images,and C. printing these subtractively color-separated negative imagesrespectively on a positive-imaging, integral tri-pack color materialthrough the corollary additively color-separation filtered white light.4. Method according to claim 3 wherein the subtractivelycolor-separating filters are cyan, magenta, and yellow-transmittingfilters, wherein the subtractively color-separated negative images arecyan, magenta, and yellow filtered images, and wherein the corollaryadditively color-separated white light is red, green, and blue filteredwhite light.
 5. Method of enhancing the information legibility oforiginal multi-color graphic material, while retaining the colors of theoriginal but reversing the density of the background of the original andthe density of the black printed information of the original, saidmethod including the steps of A. separately exposing frames ofpositive-imaging, additively color-separation dye developing,transparent materials respectively to like-color filtered, luminescentblack-and-white, negative images of the original multi-color graphic andB. superimposing, in register, the additively color-separated positiveimage transparencies.
 6. Method according to claim 5 wherein thepositive imaging, dye-developing transparent materials are red, green,and blue-dye developing transparent materials, wherein the luminescentblack-and-white negative images are red, green, and blue filtered,luminescent black-and-white negative images, and wherein the positiveimage transparencies are red dye, green dye, and blue dye positive imagetransparencies.
 7. Method of enhancing the information legibility oforiginal multi-color graphic material, while retaining the colors of theoriginal but reversing the density of the background of the original andthe density of the black printed information of the original, saidmethod comprising exposing a positive-imaging integral tri-pack colorphotographic material through red, green, and blue filters respectivelyto cyan-, magenta-, and yellow-filtered, luminescent, black-and-whitenegative images of the original multi-color graphic.
 8. Method ofenhancing the information legibility of original multi-color graphicmateria, while retaining the colors of the original but reversing thedensity of the background of the original and the density of the blackprinted information of the original, said method comprising exposing apositive-imaging integral tri-pack color photographic material throughthe red, green, and blue channels respectively of a ''''full-colorreproducing, luminescent negative image system'''' to cyan-, magenta-,and yellow-filtered images of the original multi-color graphic.